Computerized tomography studies of congenital and acquired cerebral intraventricular membranes. Report of two cases.

The role of intraventricular membranes in recurrent shunt failure is explored in two cases using computerized tomography (CT) with intraventricular metrizamide and air ventriculography. One patient who had hydrocephalus with congenital intraventricular membranes containing neurons had a good ultimate response, although he had undergone seven shunt revisions before the membranes were discovered. The other patient with postventriculitis membranes had a complicated course. The effects of shunt malposition and intraventricular antibiotic treatment are discussed. It is determined that certain clues from CT scans, plain film, and air ventriculography may indicate the presence of membranes contributing to repeated shunt failure and that the use of intraventricular metrizamide with CT facilitates the diagnosis.